A variety of laser pointers have been developed for pointing things out of a map, blackboard, etc., and have appeared on the market. FIG. 1 shows a pen-base laser pointer according to the prior art, which a combination of a laser generating apparatus and a pen. This structure of pen-base laser pointer comprises a pen 17 having an outer thread 175 at the rear end, a barrel 10 having an inner thread 151 at the front end threaded onto the outer thread 175 on the pen 17 and a radial through hole 155 at a suitable location, a clip 153 fixedly mounted on the rear barrel 10 for fastening, a laser generating unit 160 mounted inside the rear barrel 10, battery cells 170 mounted inside the rear barrel 10 and connected in series to the laser generating unit 160, and a press button 156 mounted in the radial through hole 155 and disposed above an on/off switch on the circuit board 163 of the laser generating unit 160. This structure of pen-base laser pointer is still not satisfactory in function. The drawbacks of this structure of pen-base laser pointer are outlined hereinafter.
1. The processing of the radial through hole 155 on the rear barrel 10 complicates the fabrication procedure of the pen-base laser pointer.
2. Frequently operating the press button 156 tends to damage the circuit board 163 of the laser generating unit 10.
3. Because the press button 156 protrudes from the outside wall of the rear barrel 10, the sense of beauty of the rear barrel 10 is destroyed.